Clean Line Energy Partners, which is buildng transmission lines that link renewable energy to the grid, has received a $40 million infusion from National Grid.

The equity investment will help Clean Line advance development of four long distance, high voltage direct current (HVDC) transmission lines that connect onshore wind resources with urban markets.

"Clean Line has a strong and capable development team and a portfolio of compelling projects that will advance the growth of renewable energy and the modernization of America's energy infrastructure," says Steve Holliday, National Grid CEO.

The four projects Clean Line is developing are:

The Plains & Eastern Clean Line will move 3500 megawatts (MW) of power from wind projects in western Oklahoma, southwestern Kansas, and the Texas Panhandle to communities the Southeast.

The Grain Belt Express Clean Line will deliver 3500 MW of wind energy from Kansas to Missouri, Illinois, Indiana and points farther east.

The Rock Island Clean Line will connect 3500 MW of wind energy from northwest Iowa to Illinois and other states to the east.

The Centennial West Clean Line will deliver 3500 MW of wind energy from northeastern New Mexico to communities in California.

UK-based National Grid also has a big footprint in the northeastern US. It built, operates and has a majority share in a 2000 MW HVDC line that runs between New England and Canada. It's jointly owned by 40 energy companies.

The investor-owned utility is also working with Emera Corporation to develop the Northeast Energy Link, which would span 230 miles, delivering renewable energy from Maine and eastern Canada into southern New England.